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path: root/include/linux/wmi.h
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2017-11-04platform/x86: wmi: create userspace interface for driversMario Limonciello1-0/+5
For WMI operations that are only Set or Query readable and writable sysfs attributes created by WMI vendor drivers or the bus driver makes sense. For other WMI operations that are run on Method, there needs to be a way to guarantee to userspace that the results from the method call belong to the data request to the method call. Sysfs attributes don't work well in this scenario because two userspace processes may be competing at reading/writing an attribute and step on each other's data. When a WMI vendor driver declares a callback method in the wmi_driver the WMI bus driver will create a character device that maps to that function. This callback method will be responsible for filtering invalid requests and performing the actual call. That character device will correspond to this path: /dev/wmi/$driver Performing read() on this character device will provide the size of the buffer that the character device needs to perform calls. This buffer size can be set by vendor drivers through a new symbol or when MOF parsing is available by the MOF. Performing ioctl() on this character device will be interpretd by the WMI bus driver. It will perform sanity tests for size of data, test them for a valid instance, copy the data from userspace and pass iton to the vendor driver to further process and run. This creates an implicit policy that each driver will only be allowed a single character device. If a module matches multiple GUID's, the wmi_devices will need to be all handled by the same wmi_driver. The WMI vendor drivers will be responsible for managing inappropriate access to this character device and proper locking on data used by it. When a WMI vendor driver is unloaded the WMI bus driver will clean up the character device and any memory allocated for the call. Signed-off-by: Mario Limonciello <mario.limonciello@dell.com> Reviewed-by: Edward O'Callaghan <quasisec@google.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-11-04platform/x86: wmi: Don't allow drivers to get each other's GUIDsMario Limonciello1-4/+0
The only driver using this was dell-wmi, and it really was a hack. The driver was getting a data attribute from another driver and this type of action should not be encouraged. Rather drivers that need to interact with one another should pass data back and forth via exported functions. Signed-off-by: Mario Limonciello <mario.limonciello@dell.com> Reviewed-by: Edward O'Callaghan <quasisec@google.com> Reviewed-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-11-04platform/x86: wmi: Add new method wmidev_evaluate_methodMario Limonciello1-0/+6
Drivers properly using the wmibus can pass their wmi_device pointer rather than the GUID back to the WMI bus to evaluate the proper methods. Any "new" drivers added that use the WMI bus should use this rather than the old wmi_evaluate_method that would take the GUID. Signed-off-by: Mario Limonciello <mario.limonciello@dell.com> Reviewed-by: Edward O'Callaghan <quasisec@google.com> Reviewed-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06platform/x86: wmi: Require query for data blocks, rename writable to setableDarren Hart (VMware)1-5/+2
The Microsoft WMI documentation requires all data blocks to implement the Query Control Method (WQxx). If we encounter a data block not implementing this control method, issue a warning, and ignore the data block. Remove the "readable" attribute as all data blocks must be readable (query-able). Be consistent with the language in the documentation, replace the "writable" attribute with "setable". Simplify (flatten) the control flow of wmi_create_device a bit while we are updating it for the above changes. Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Pali Rohár <pali.rohar@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-acpi@vger.kernel.org Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-06platform/x86: wmi: Add an interface for subdrivers to access sibling devicesAndy Lutomirski1-0/+4
Some subdrivers need to access sibling devices. This gives them a clean way to do so. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Pali Rohár <pali.rohar@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-acpi@vger.kernel.org Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06platform/x86: wmi: Add a new interface to read block dataAndy Lutomirski1-0/+4
wmi_query_block is unnecessarily indirect. Add a straightforward method for wmi bus drivers to use to read block data. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Pali Rohár <pali.rohar@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-acpi@vger.kernel.org Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06platform/x86: wmi: Incorporate acpi_install_notify_handlerAndy Lutomirski1-0/+1
As a platform driver, acpi_driver.notify will not be available, so use acpi_install_notify_handler as we will be converting to a platform driver. This gives event drivers a simple way to handle events. It also seems closer to what the Windows docs suggest that Windows does: it sounds like, in Windows, the mapper is responsible for called _WED before dispatching to the subdriver. Signed-off-by: Andy Lutomirski <luto@kernel.org> [dvhart: merge two development commits and update commit message] Cc: Andy Lutomirski <luto@amacapital.net> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Pali Rohár <pali.rohar@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-acpi@vger.kernel.org Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06platform/x86: wmi: Probe data objects for read and write capabilitiesAndy Lutomirski1-0/+6
The Dell XPS 13 9350 has one RW data object, one RO data object, and one totally inaccessible data object. Check for the existence of the accessor methods and report in sysfs. The docs also permit WQxx getters for single-instance objects to take no parameters. Probe for that as well to avoid ACPICA warnings about mismatched signatures. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Pali Rohár <pali.rohar@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-acpi@vger.kernel.org Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06platform/x86: wmi: Turn WMI into a bus driverAndy Lutomirski1-0/+47
WMI is logically a bus: the WMI driver binds to an ACPI node (or more than one), and each instance of the WMI driver enumerates its children and hopes that drivers will attach to the children that are useful. This patch gives WMI a driver model bus type and the ability to match to drivers. The bus itself is a device in the new "wmi_bus" class, and all of the individual WMI devices are slotted into the device hierarchy correctly. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Pali Rohár <pali.rohar@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-acpi@vger.kernel.org Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>